Ok so we had a couple cracks in the middle aluminum case of our LT80, so I tore it all down and hade the case welded. Once I got it all back together it fired up great but the wheels would barely turn whith any sort of weight on the quad if you lift the rear tires off the ground it runs great. Seems like it doesn't want to wind up very much unless the wheels are off the ground. Checked compression and its 120psi. Can someone take a look at the attached pictures I think the timing is off and the two lines in the picture need lined up I think these are the timing marks? Would this be causing the problem? Not much of a mechanic but I am learning..
Thanks!

 

Yes, the marks need to be aligned.
If that don't fix it, I'd get into the clutchs.

 

Aligned the timing marks, seemed like it sounded better but still no power. It runs but wont even run over my foot if I stick it in front of the rear wheel. Tore the front clutch down and two of the rollers had flat spots, would this cause the lower power issue?

 

Possibly. Def needed clutch maint. You need to check the rear clutch bearings (they go bad).
I suspect a plugged pipe.

 

Maybe a dumb question but it there a way to check for a plugged pipe? Ive ordered a new set of rollers for the front clutch but they wont ne here for a few day. How you unplug the pipe?

 

To clean, take it off, stick it in a fire/charcoal/etc and get it red hot. Blow compressed air thru it. CAREFUL, it'll throw flames.